Edmund graham and george bowman



E. GRAHAM AND G. BOWMAN.

FLUID PRESSURE JACK.

APPLICATION FILED SEPT. 9. 1918.

1,828,688., r Patented Dec. 2,1919.

up mu u EDMUND GRAHAM AND GEORGE BOWMAN, 0F BELFAST, IRELAND.

FLUID-PRESSURE JACK.

mes es.

Specification of Letters .Patent.

Patented lDec. 2, 1919.

Application filed September 9, 1918. Serial No. 253,158.

To all whom it may concern:

Be it known that we, EDMUND GRAHAM,

of'Dunottar, Kings Road, Knock, Belfast, Ireland, and GEORGE BOWMAN, ofBallygomartin Road, Belfast, Ireland, both subjects of the King of GreatBritain and Ire- I land, have invented certain new and usefulImprovements Relating to Fluid-Pressure Jacks, of which the following isa specificatron.

This invention relates to liquid or other fluid pressure operated jacksfor use in connection with the jacking up of motor or like vehicles, itsobject being to provide improvements in the means for returning the ramof each jack after the pressure is withdrawn.

Under our invention the ram of the jack is returned by a plurality ofcoacting springs. The springs may be arranged to act under eithercompression or tension or under compression and tension and the ram ismade hollow for their reception.

We have hereunto appended explanatory drawings showing some examples ofram returning means, in accordance with our invention.

Figure 1 is a sectional elevation of a jack in which the ram is returnedby means of two compression springs.

Fig. 2 is a sectional elevation of a jack in which the ram is returnedby a combina-,

tion of compression and tension springs.

Referring to the drawings In the example shown at Fig. 1 we employ twocompression springs 1 and 2 to give the necessary spring return actionon the ram 3 of the ack 4, The springs 1 and 2 are concentricallyarranged the spring 2 being within the spring 1 and both springs withinthe ram3. The outer spring 1 bears, at its top, against a projectingring 5 within the ram 3 while its lower end rests on a flange 6 on thelower end of a tube or sleeve 7 located between the springs. The innerspring 2 bears, at its upper end, against the underside of an inwardlyprojecting ring 3 at the top of and movable with the sleeve 7 and at itslower end, bears on a ring or plate 9 which may be fixedly andadjustably connected by a rod 10 with the top 4 of the jack b meansofthe threaded extremity 10 am the nut 10". The sleeve 7 is adapted toslide over the fixed plate 9 and the latter is shown capable ofadjustment for the purpose of varying the compression on the springs.The arrangement is such that when the liquid or fluid forces the ram 3down the springs will be compressed and as the ram extends beyond thejack casing 4 the. sleeve 7 will extend outward with it over the fixedplate 9. When the fluid pres sure is withdrawn'both springs will reactto return the ram 3.

Instead of the two compression springs as above described we may employ,as shown 1n Fig. 3, a compression spring and a tenslon spring used incombination. In this case the ram 3 and jack casing 4 are made the sameas the corresponding parts shown in Fig. 1 and both springs areaccommodated within the ram 3. The compression spring 11 bears, at itsupper end, on the proectmg ring 5 and, at its lower end, on a plate 12movable within the ram 3 and connected to one end 13 of the tensionspring 13 and its other end may be fixedly and ad justably secured tothe top 4 of the jack casing 4 by means of the anchor bolt 13 and athreaded portion 13 and a nut 13 (206perating therewith. The arrangementis such that when the fluid pressure forces down the ram 3 thecompression spring 11 will be compressed against the plate 12 until thepressure commences to pull on the tension spring 13 which will then beextended and the plate 12 will move with the movement of the tensionspring 13 carrying with it the compression spring until the limit ofmovement of the ram 3 has been reached. When the fluid pressure iswithdrawn both springs will react to return the ram and may, for someportion of return action, be re-acting together.

Having now fully described our invention what we claim and desire tosecure by Letters Patent is:

1. A liquid or other fluid pressure jack for jacking up-vehicles havinga hollow ram and two springs located in said. ram, and means also withinthe ram, interposed between, and upon which means both springs act forthe purpose of returning the jack after the pressure thereon has beenrelieved. I

e 2. A liquid or other fluid pressure jack for jacking up vehicleshaving a hollow ram. two springs both acting under compression locatedin said ram, one within the other, and means interposed between thesprings and upon which means 'both springs act whereby the spring, willcooperate for the purpose of returning the jack after the pressurethereon has been relieved.

3. A liquid or other fluid pressure jack for jacking up vehicles havinga hollow ram, a tubular member within said ram, and two co-actingsprings located in said ram the one within the ram and the other withinthe tubular member, and means whereby when the ram is forced outwardboth springs are compressed simultaneously.

4. A liquid or other fluid pressure ack for jacking up vehicles having ahollow ram and two co-acting springs located in 15 said ram the onespring being fixedly held atone end and at its other end cooperatingwith a movable member, and the other spring being outside the firstmentioned spring and seated at one end against the top of theram and atthe other end against said movable member.

5. A liquid or other fluid pressure jack for jacking up vehicles havinga hollow ram and two, co-acting springs located in one end against thetop of the ram and at the other end against an element movably fitted inthe rain, the inner spring being anchored at one end to the casing andat the other end upon the said element.

7. A liquid or other fluid pressure jack for jacking up vehicles havinga hollow ram and two co-acting springs therein and a member acted on byand located between the springs said member being slid-ably fittedWithin the ram.

8. A liquid or other fluid pressure jack for jacking up vehicles havinga hollow ram, two springs located in said ram, means anchoring the onespring to the casing, and means within the ram and between the springswhereby the two springs are caused to co-act.

9. liquid or other fluid pressure jack for jacking up vehicles having ahollow ram, two springs located in said ram, means anchoring the onespring to the casing. and means within the ram whereby the two springsare caused to co-act, said means consisting of a movable member acted onby both springs.

10. A liquid or other fluid pressure jack for jacking up vehicles andhaving a hollow ram, two springs located in said ram. means anchoringone of the springs to the casing, and means within the ram whereby thetwo springs are caused to co-act, the last said means embodying amovable element acted upon by both springs, the last said means alsoembodying a tubular member interposed between the springs andencompassing one of the springs.

In testimony whereof we aflix our signatures in presence of twowitnesses.

EDMUND GRAHAM. GEORGE BOWMAN.

Witnemes:

- ANDREW HAMILTON,

JOHN Knox.

